1. Field of the Invention
The present invention relates to improvements in railroad coupler mounts and, more particularly, railroad coupler mounts for attaching an end-of-train device (EOT), marker light, test gear, or other equipment to a railroad coupler.
2. Description of the Background
Railroad couplers are designed to connect rail cars together to form the train and generally have no provision to mount other devices or equipment. However, railroads often need to mount end-of-train telemetry devices (EOTs), marker lights, test equipment or other devices to the same railroad car coupler.
Several railroad mounts for EOTs, marker lights and/or other apparatus have been devised using the coupler knuckle or other coupler features that are active when mating two couplers together (See U.S. Pat. No. 2,355,544 to McGowan, U.S. Pat. No. 4,487,060 to Pomeroy, U.S. Pat. No. 4,592,217 to Fernandez et al, U.S. Pat. No. 4,747,302 to Goss and U.S. Pat. No. 5,287,739 to Kingsbury). However, when mating two couplers, mounts using or in close proximity to the coupler mating features prevent the couplers from mating or expose the mount and equipment to severe damage without first removing the mount and equipment from the coupler. It is desirable that a mount can remain attached to the coupler and not impede mating with another coupler and that no damage occur to the mount or equipment when mating to another coupler. Conventional railroad couplers (as shown in FIG. 1) are typically cast with four holes 2a, 2b, 3a and 3b on the guard arm face. These holes are typically arranged in two vertical pairs with two holes forward (2a, 3a) and two holes further back along the horizontal length of the coupler (2b, 3b). The top and bottom sets of holes each connect with a horizontal passage, and the passages are separated with a horizontal rib (4a, 4b). These coring holes and passages are only designed to facilitate the coupler casting process and lessen the coupler weight, but are otherwise unused in normal coupler operations. Several railroad coupler mounts have been devised to use these coring holes and passages as a means of attachment to the couplers.
For example, U.S. Pat. No. 4,520,662 to Schmid, U.S. Pat. No. 4,665,858 to Harrigal et al, U.S. Pat. No. 4,876,885 to Martin et al, U.S. Pat. No. 4,691,563 to Martin, U.S. Pat. No. 5,131,269 to Blosnick et al and U.S. Pat. No. 5,176,350 to McQuistian show a variety of claw-like and other mechanisms that lengthwise span adjacent coring hole pairs, thereby anchoring the mount to side-by-side coupler holes. However, (as seen in FIG. 1) the span between 2a/2b and 3a/3b is typically much wider than the narrow 2a/3a and 2b/3b span. Coring hole geometry is not standardized and there is broad variation from coupler to coupler of the lengthwise coring hole span, but vertical coring holes are consistently separated with a ½ to 1″ thick rib. Mounts that grip the side-by-side coring holes are larger and heavier than mounts using vertical coring holes because of the additional lengthwise span and the greater adjustment stroke needed to compensate for lengthwise span variability. Consequently, mounts that employ coring hole anchors large enough to span lengthwise coring hole pairs are inevitably heavy and often protrude beyond the equipment to be mounted, and this makes carrying the equipment more difficult. Dismounted equipment is often carried at the user's side, and the propensity of the protruding mount to bump the user's leg or catch on clothing presents a safety hazard. Safety and ergonomics make it desirable that a coupler mount eliminate or minimize protrusions beyond the width of the equipment and that the mount be as light weight as possible.
U.S. Pat. No. 5,235,849 to Egerton and U.S. Pat. No. 6,135,665 to Alfieri, et al use a hook or finger that fits into a single top coring hole. Fitting into a single core hole helps to keep the mount compact, but the mounts require the hook or finger to react with additional mount components (the jaw in the '849 patent or 2nd and 3rd fingers in the '665 patent) that bear on the coupler rib. These additional mount components must be independently fabricated from the hook or finger and complicate manufacture of the mount. U.S. Pat. No. 6,588,966 to Kane, et al. show expanding jaws that fit to the top and bottom edges of a vertical pair of coring holes. This keeps the mount compact, but both jaws must pivot to fit variable coupler hole geometry, and the device requires multiple scissor arms with multiple pivots or a geared screw to actuate, which complicates manufacture of the mount. All of these devices are actuated by screws that must be rotated by hand many turns to move the hook, finger or jaws through the range of motion. This makes installation or removal of the mounts slow and tedious.
What is needed is a simple, inexpensive, lightweight and reliable mount that facilitates quick and easy installation and removal from a coupler, and which does not interfere with any coupler mating features so as to allow mating to another coupler without removing the EOT.